Registering renewable plug fuse



Jan. 29, 1929. 1,700,356

J. P. GILLIAM ,REGISTERING RENEWABLE PLUG FUSEy Filed May lll 1927 Patented Jan. 29,v 19279.

UNITED y STATES vPii'lElsx'r OFFICE.

JAMES GILLIAM, OF LOS ANGELES, CALIFORNIA, ASSIGNOR OF ONE-HALF T HENRY W. BERKHEYEB, 0F GLENDALE, CALIFORNIA.

REGBTEBING BENEWAIBLE :PLUG FUSE.

Application mcd Hay 11,

My invention is a registering renewable plug fuse of the type having a screw threaded plug by which it may be secured in a socket,

and including a fuse to break theelectrical .j circuit of which it forms a part in the event of overload or short circuit.

An object of my invention is the construction of a registering renewable plug fuse preferably of the screw type, in which when lo the fuse is broken an indication is given by the movement of one of the plug elements showing that such fuse has been burned..

In constructing my invention I utilize a tubular insulating body with a screw threaded jacket thereon to form one terminal'. In-

side of the body I have a contacting spring enga with the conductingjacket. A core is 'slidalble in the main insulating body and is constructed of insulating material. This has a conducting element thereon to engage the contact spring and on the end of the core is a second terminal. rIhe fuse in the form of a loop or a bar with perforations is secured to the endlterminal and to the conducting element on the core. This holdsa slidable part of the core in retracted position against the action of the compression spring and, on releasing of the fuse, part of the core is thrust outwardly.

My invention is illustrated in the accompanying drawings, in which Figure 1 is a longitudinal sectional view of the fuse plug, the plane of section being taken on the line 1-1 of Fig. 2.

Figure 2 is a transverse sectional view taken on the line 2-2 of Fig. 1 in the direction of the arrows.

Figure 3 is a sectional view similar toV Fig. 1 with the movable end of the core thrustv outwardly.

Figure l4 is an inner end view of the plug,

Vthe direction of view'being indicated by the arrow 4 o :LFigure 3.

Figure 5 is a longitudinal sectional view 5 taken on the line 5-5 of Fig. 1 in the direction of the arrows.

` Figure 6 is a side view of the plug, taken in the direction'of the arrow 6 of Fig. 1, with the conducting jacket removed.

Figure 7 is an outer end view of the plug,

taken in the direction of the arrow 7 of Fi A`Figure 8 is a. side view of the core, ta au in the direction of the arrow 8 of Fig. 9.

Figure 9 is a view of the core, taken in the` ducting plate 46 1s secured to this tubular 11n direction of the arrow 9 of Fig. 8.

fend, a cylindrical part 13 adjacent thereto, a

1927. Serial N0. 180,503.

Figurezlis a view of the core, taken in the dlrection of the varrow 10 of Fi 9. t Figure 11 is a detail perspective view of the contact spring.

Figure 12 is a view of the core, similar to Fig. 8, with the fuse ring. removed and the head thrust outwardly.

' The outside bod of the plug comprises a tubular shell 11'w ich has a head 12 at one screw threaded section 14, and a small end 15. Thls shell has a hexagonal internal bore 16. A slot 17 is cut-through one side of the shell, preferably at the screw threaded part, and part of these threads are cut away at an ad'acent party 18. The shell is provided with longitudinal grooves 19 in the walls of the bore 16. A conducting jacket 20k is threaded on the screw threads andl underneath this jacket is a conducting spring 21. This spring has a flat portion 22 with -a flange 23, the flange fitting over the end 24 of the screw threads 14. The spring 21 also has asection 25 bent inwardly and a reverse bend 26, there being a flat contacting part 27 with a longitudinal slot 28 therethrou h, the piece terminating with an inwardly l(luent flange 29, the slot extending partly into said flange. (See Fig. 11.) This Contactin spring is held in position by being jamme 4by the' jacket 20 against that portion 18 of the shell from which the threads have been cut away.

The core, designated generall by the numeral `30, has a stationary or ase part 31 t which is hexagonal on the outside and has ab longitudinal ribs 32 sliding in the grooves 19. The base 31 has a head 33 fitting in a seat 34 against a shoulder in the end of the shell.` A deep recess 35 is formed in the base, extending from the end 36, and there are a pair of slots 37 and 38 which extend through the wall of the base into this recess. A conductsulating material.

The indicating head'42 ofthe core has an 105 endlor head piece. 43, preferably formed of insulating material, which is screw threaded i on a tubularbar 44, there vbeing a shoulder 45 to limit the threading of the head. A con- `46, urges the indicating head and the tubular bar 44 outwardly, this motion or the bar 44 and head 42 being normally prevented by the y fuse 49.

The manner oit' operation and functioning of my plug is substantially as follows:

When the various elements of the plug are assembled and the fuse fitted over the prongs 41 and 48, it will be seen that this fuse holds the base part and the movable head section of the core together, with the spring 51 corn-v pressed. The plate 46, 'after being iitted in the shell, presses the end of the fuse on the prong 48 against the portion 27 of the conducting spring 21, the prong sliding in the slot 28. Therefore, the plug when inserted in thexsooket yforms an electric connection through the jacket 20, the spring 21, the conducting plate 46, the fuse 49, the prong 41, the conducting plate or strip 39 and the screw 40, the head of the screw 40 and the jacket 20 forming the contacts in the socket.

lf the fuse burns, the resistance restraining the spring 51 is removed and the spring thrusts the movable head of the core outwardly from the position shown in Fig. 1 to that shown in Fig. 3. rlheretore, a person inspecting the plug may readily ascertain by noting the head end 43 thrust outwardly that the :tuse has been burned in thisplug. it will thus be seen that in installations in which a large number of Jfuse plugs are required, that Va quick inspection will show which particular plug or plugs are fused. Suchplugs may then be unscrewed from the socket, the core may then be readily withdrawn, and a new fuse bar placed on the prongs 41 and 48, Vthe core being then reinserted in the shell and vthe whole plug again connected in the socket.

A portion of the Aconducting plate 46 adjacent the prong`48 has a flat end 52 and the end 53 of the conducting strip 39 adjacent the prong 41 is also flat, as shown in Fig. 12. These flat surfaces give suilicient area for the transmission of current through the fuse link which is connected onto the prongs.l One end of the link is pressed against the end 52 by the Aspring' 21.

The tubular bar 44 may be utilized as a receptacle for spare fuse links or bars, as when the core is removed the head 43 may be unscrewed from this tubular bar. It is to be noted, however, that when the plug is assembled that. the head 43 cannot be unscrewed even when thrust outwardly into the position shown in Fig. 3, and it will be necessary links.

Variouschanges may be made in the principles of my invention without departing from the spirit thereof, as set forth in the f description, drawings and claims- I claim: I 1-. A fuse plug having a tubular shell with a Contact element thereon, a core fitting in the shell having a stationary base with a con# tact element thereon, a slidable head in the core, means normally thrusting said head outwardly, a conducting structurebetween the contact element on'the shell and the head, a

fuse bar connected between the head and the contact end'oi:l the base holding said head in retracted position.

2. A fuse plug comprising in combination a tubular shell having an electrical contact thereon, a core having a stationary base with a second contact, the core having a slidable head with a conducting element, a conducting means between the contact and the shell and the said conducting element, a use bar, `means to connect said fuse bar between the conducting element on the head and the contact on the base, and means to thrust the head outwardly on the fusing of said bar.

3. A use plug having a tubular shell with a screw threaded conducting jacket thereon, a core having a base iting in said shell, the base having a contacting and a conducting element thereon, a head slidably mounted in the core having 'a conducting plate, a fuse bar .connected between the conducting plate and the conducting element on the base, a conducting spring between the 'jacket and the said conducting plate, and a compression spring in the core thrusting the head outwardly on fusing of the fuse bar.

4. A fuse plug having a tubular shell with a conducting jacket thereon, a core having a base insertable in the shell from the. inner end, a head slidably mounted in the core in relation to the said base, a prong connected to the head and to the base, a fuse bar attached to said prongs, a contactinfthe base connected to the prong thereon, means to form an electrical connection from the prong on the head to the said jacket, and a spring in the core tensioned to thrust said head upwardly on'the fusing of said fuse bar.

5. A use plug comprising in combination a tubular shell having a conducting jacket with screw threads, a conducting resilient strip extending from the outside to the inside of said'shell and engaging the 'conducting jacket, av core having a base with a recess and a contact screw with a conduct-ing strip conconnection between said plate and the resilient strip, a fuse bar between the conducting plate and the conducting strip on the base, and a spring bearing against 1Hoe head to thrust same outwardly on fusing o the bar. '6. A fuse plug having a cyinrica shell with a conducting jacket thereon, said shel having a slot with a lresilent conoluctng strip tnng thefein, said strip having an electrical connection' wich the jacket, a core nsertable v in the shell and having a base wich a contactimg and a conducting strip on its end, a prong on the conducting strip, a head sa'be in the cox'e having a conducting plate thereon, a prong on said plate, a fuse bar tted on said prongs on the plate and the conducting 15 strip? the conducting pate forming an elec- :tric connection with the resem strip, ano

a spring in 'the core healing against the oase anol the said head to force the sa head omis" Wardy on the fusing o' the ha?.

'base having latefa sos9 'che said condos@- ng pabe extending though said sots, 'these being recess im 'the base9 and Seidl spffmc;

being housed in said accesse A. 'fuse plug, as camec i xeslent st-p having slot? an the conducting plate im sai sloa.

lm testimony whereof my name to this specification., 

